1. Field of the Invention
The present invention is directed to a magnetic resonance transmission antenna of the type having at least two transmission elements that individually generate respective, linearly polarized, discrete magnetic fields that are superimposed to form a circularly polarized, overall magnetic field.
2. Description of the Prior Art
Magnetic resonance transmission antennas of the above general type are wellknown, for example, in German OS 44 34 948, German OS 43 22 352, German OS 41 38 690, U.S. Pat. Nos. 5,144,241 and 5,606,259.
In these known antennas, currents that are offset in phase by 90.degree. are supplied into two transmission elements in order to generate the circularly polarized, overall magnetic field. To this end, a transmission current is divided into two sub-currents that are offset in phase by 90.degree. relative to one another and that are set to the same amplitude in matching circuits. The sub-currents are then supplied into the transmission elements. The transmission elements are decoupled from one another in a complicated way in order to avoid unwanted couplings and to thus obtain a purely circularly polarized, overall magnetic field.